Adding field name to ExtensionConfigurationException message (#1488)

CONTRIBUTING.md

@@ -8,5 +8,9 @@
 	* discuss with the authors on an issue ticket prior to doing anything big
 	* follow the style, naming and structure conventions of the rest of the project
 	* make commits atomic and easy to merge
-	* verify all tests are passing. Build the project with `./gradlew check` to do this.
-	**N.B.** Gradle's Build Cache is enabled by default, but you can add `--no-build-cache` flag to disable it.
+	* verify all tests are passing. Build the project with `./gradlew check` to do this
+
+	**PS:** Make sure Docker is running locally and you have the lombok plugin installed in your IDE
+
+	**N.B.** Gradle's Build Cache is enabled by default, but you can add `--no-build-cache` flag to disable it.
+

modules/junit-jupiter/src/main/java/org/testcontainers/junit/jupiter/TestcontainersExtension.java

@@ -95,7 +95,7 @@ private static Predicate<Field> isContainer() {
                 boolean isStartable = Startable.class.isAssignableFrom(field.getType());
 
                 if (!isStartable) {
-                    throw new ExtensionConfigurationException("Annotation is only supported for Startable types");
+                    throw new ExtensionConfigurationException(String.format("FieldName: %s does not implement Startable", field.getName()));
                 }
                 return true;
             }